Orthodontic treatments involve repositioning misaligned teeth and improving bite configurations for improved cosmetic appearance and dental function. Repositioning is often accomplished by applying light continuous forces to a patient's teeth over an extended period of time. As part of the process of moving from the initial dental configuration to the final desired end configuration, the teeth typically undergo a transition through a series of intermediate configurations.
Conventionally, repositioning of teeth has been accomplished by what are commonly referred to as “braces.” Braces comprise a variety of appliance components such as brackets, bands, archwires, ligatures, and O-rings. After the brackets and bands are affixed or bonded to the teeth, periodic meetings with the orthodontist are required so that the orthodontist can reactively adjust the archwires to create a new directional forces that continue to move the teeth closer to the desired position. This may involve installing different archwires having different force-inducing properties, adjusting the shape of the archwires, and/or replacing or tightening the ligatures that secure the wire to the fixed appliance.
An alternative to braces includes the use of aligner-type dental appliances for realigning teeth. Such an appliance may be comprised of a thin shell of material that forms a receiving cavity geometry that generally conforms to a patient's teeth but is slightly out of alignment with the initial tooth configuration. Placement of the dental appliances over the teeth applies controlled forces in specific locations to gradually move the teeth into a new predetermined configuration. Repetition of this process with successive appliances comprising new configurations eventually moves the teeth through a series of predetermined intermediate arrangements along the most effective and efficient treatment path to a final predetermined arrangement.
Aligner-type dental appliances may only be effective over a certain period of time due to the limited effective range of the active components of the appliance. After a certain time, the usefulness of the dental appliance is reduced by moving the teeth to the desired location, by a loss in resiliency in the dental appliance, or a combination of the two. Once the usefulness of the aligner dental appliance is reduced, the dental appliance is typically disposed of, and the next dental appliance in the treatment series is used. Hence, the shorter the useful lifespan of the dental appliance, the more frequently the dental appliance needs to be changed or adjusted. Consequently, a reduction in the lifespan of the dental appliance can require a greater number of dental appliances to achieve a desired dental result.